Engine stalls while driving at idle?

After replacing battery, I immediately starting having problems with my truck dying when put in gear. I had not had this problem before. I would have to start the truck in neutral and keep one foot on the gas and one on the brake, then slip it into gear to take off. This happened intermittantly for 6-8 months. The past month it became increasingly difficult to keep the truck running long enough to get it into gear. About 2 weeks ago it quit completely. It would start but immediately die. It threw 3 codes.P0506, P0171 and P0401. This Explorer does not have an IAC valve as it is drive-by-wire. We replaced the Throttle Position Sensor. Once that was done the truck would idle in Park and in Drive, but had NO acceleration. Truck then threw codes P2111 and P2104. Replaced the Throttle Pedal. Still no acceleration and once again have the original problem that truck will not idle.

Hi there!
Your troublecodes are still indicating a Throttle Actuator control problem. (Which I'm sure you already knew) My suggestion would be to get a wiring diagram for the engine/emission controls. In most cases the onboard computer sends reference voltage to the TPS. The TPS is typically just a coil that tightens up when the throttle is opened and that changes the resistance of the coil, which changes the output signal back to the computer - which is one way it the computer calculates engine load. Before I replaced anything else, I would get a volt meter (or someone who has one and knows how to use it) and check the control circuit for that reference voltage. - Your service manual should tell you what it should be. If it's not in the correct range, you'll need to backtrack that circuit to trace the problem.
It may also be worth it to you to pay a shop to read data stream info with their diagnostic machine, which will be much more specific than a code reader.
Hope that helps. Good luck!

PS - I suspect the timing in relation to the battery replacement is just a coincidence, but stranger things have happened.

When I drive my car for about 30 minutes or longer and come to a stop sign or traffic light, the car cuts off. Im able to crank the car back up and continue driving. Sometimes, I give it press the gas pedal to keep it from cutting off. Secondly, sometimes when I'm driving I start slowing down way before I get to the stop sign and it starts acting like its going to cut off when I make my turn left or right and I have to keep pressing the gas pedal to keep it from cutting off.

Good fuel pressure, no vaccum leaks and the engine light doesn't come on. I've changed the oxygen sensors, idle control valve.

I turn my 2004 ford explorer on and when I put it in drive it starts to stall then it turns off what could the problem be